Warnings fix
Play sounds/main_menu.ogg in menu
Fix warnings in mapblock.cpp
Add VBO (with setting in minetest.conf, default false)
Add support for setting stepheight for entities
Make bumpmapping compatible with irrlicht 1.8
Leveled nodebox backward compatibility
Weather backward compatibility
Allow multiple 'wherein' nodes in oredef
Merge 'upstream/master' into minemovie